Such a cutting insert is described for instance in DE 42 39 236 A1. The longitudinal ribs described therein have in there longitudinal section a minimum and a maximum in a region away from the cutting edge, or are at the same level as a central face plateau raised with respect to the cutting edges or corners. Seen in cross section, the longitudinal ribs can have a constant width over their entire longitudinal axis or can become wider towards a region located at a distance from the cutting edge. In the case of relatively large initial curvature radii of the removed chip, particularly when the cutting element is used with small advance, these ribs make it possible to bend up the chip as much as possible. In the case of high advance rates, due to the maximum or greatest height located at a distance from the cutting edge it is possible to act counteract a very small initial curvature radius, i.e. a very tight curling of the chip.
A cutting insert having longitudinal ribs with a parabolic cross section, arranged along the cutting edge at identical acute angles, is described in DE 41 18 070 A1. Cutting inserts with longitudinal ribs having at least one recess reaching up to the cutting face, are described in the WO 92/21467. Finally there are also known cutting inserts with raised cutting elements or a median raised face plateau which has nose-like or wedge-like projections pointing in the direction of the cutting corner or cutting edge.